An electrophotographic image forming apparatus is configured to expose photosensitive members, thereby forming electrostatic latent images on the surfaces of the photosensitive members, and supply developer to the electrostatic latent images, thereby forming developer images, and the image forming apparatus transfers the developer images onto a recording sheet or the like, thereby forming an image on the recording sheet or the like. In this image forming apparatus, in order to form a good image, it is necessary to appropriately set control parameters such as a transfer current, a charging bias, and a discharging light amount necessary after transfer. These control parameters depend on the characteristics of the photosensitive members.
Since the characteristics of photosensitive members slightly differ from manufacturer to manufacturer, or from manufacturing lot to manufacturing lot, in the background art, in order to identify photosensitive members, identification information items using slit arrangements are provided to members rotating according to rotation of photosensitive members or IC tags are provided to photosensitive members or cartridges including photosensitive members.